文摘
The photo-induced vapor-phase decompositions of formic acid and methyl formate were investigated on pure, N-doped and Au-promoted TiOb>2b>. Infrared (IR) spectroscopic studies revealed that illumination initiated the decomposition of adsorbed formate formed in the dissociation of formic acid and located mainly on TiOb>2b>. The photocatalytic decompositions of formic acid and methyl formate vapor on pure TiOb>2b> occurred to only a limited extent. The deposition of Au on pure or doped TiOb>2b> markedly enhanced the extent of photocatalytic decomposition of formic acid. The main process was dehydrogenation to give Hb>2b> and COb>2b>. The formation of CO occurred to only a very small extent. Addition of Ob>2b> or Hb>2b>O to the formic acid decreased the CO level from ¡«0.8 % to ¡«0.088 % . Similar features were experienced in the photocatalytic decomposition of methyl formate, which dissociated in part to give surface formate. Experiments over Au deposited on N-doped TiOb>2b> revealed that the photo-induced decomposition of both compounds occurs even in visible light.